diff --git a/mu-plugins/fea-audio-player.php b/mu-plugins/fea-audio-player.php
index b8642e2..9394070 100644
--- a/mu-plugins/fea-audio-player.php
+++ b/mu-plugins/fea-audio-player.php
@@ -13,11 +13,23 @@ function fea_audio_player_html(): string {
     $url = get_post_meta($id, 'fea_audio_url', true);
     if (!$url) return '';
     $voice = get_post_meta($id, 'fea_audio_voice', true) ?: 'NicoFeadulta2026';
-    return '<div class="fea-audio">'
-        . '<span class="fea-audio-label">'
+    $sha256 = get_post_meta($id, 'fea_audio_sha256', true);
+    $label = '<span class="fea-audio-label">'
         . '<svg viewBox="0 0 24 24" width="16" height="16" aria-hidden="true" focusable="false">'
         . '<path fill="currentColor" d="M3 10v4h4l5 5V5L7 10H3zm13.5 2a4.5 4.5 0 0 0-2.5-4.03v8.06A4.5 4.5 0 0 0 16.5 12zM14 3.23v2.06a7 7 0 0 1 0 13.42v2.06a9 9 0 0 0 0-17.54z"/>'
-        . '</svg> Escucha</span>'
+        . '</svg> Escucha</span>';
+    // Para un asset con hash registrado, descarga y verifica el fichero completo
+    // antes de delegar playback al navegador. Evita que un stream Range mezclado
+    // por una caché reproduzca fragmentos de otro MP3.
+    if (preg_match('/^[a-f0-9]{64}$/i', $sha256)) {
+        return '<div class="fea-audio">' . $label
+            . '<button type="button" class="fea-audio-verified-play" data-fea-audio-verified-play'
+            . ' data-src="' . esc_url($url) . '" data-sha256="' . esc_attr(strtolower($sha256)) . '"'
+            . ' data-post-id="' . esc_attr($id) . '" data-voice="' . esc_attr($voice) . '">Reproducir audio</button>'
+            . '<audio controls preload="none" hidden data-fea-audio-track data-post-id="' . esc_attr($id) . '" data-voice="' . esc_attr($voice) . '"></audio>'
+            . '<span class="fea-audio-status" role="status" aria-live="polite"></span></div>';
+    }
+    return '<div class="fea-audio">' . $label
         . '<audio controls preload="none" src="' . esc_url($url) . '"'
         . ' data-fea-audio-track data-post-id="' . esc_attr($id) . '" data-voice="' . esc_attr($voice) . '"></audio>'
         . '</div>';
@@ -56,6 +68,9 @@ add_action('wp_head', function () {
     .fea-audio-label{display:inline-flex;align-items:center;gap:.35rem;font-size:.78rem;
         font-weight:600;color:#8b1a2e;white-space:nowrap;line-height:1}
     .fea-audio audio{height:32px;width:230px;max-width:44vw}
+    .fea-audio-verified-play{border:1px solid #8b1a2e;border-radius:6px;background:#fff;color:#8b1a2e;padding:.35rem .6rem;font:inherit;font-size:.82rem;font-weight:600;cursor:pointer}
+    .fea-audio-verified-play:disabled{opacity:.65;cursor:wait}
+    .fea-audio-status{font-size:.76rem;color:#6b5c60}
     @media(max-width:600px){
         .fea-audio{margin-left:0;width:100%;margin-top:.5rem}
         .fea-audio audio{flex:1 1 auto;width:auto;max-width:none}
@@ -73,17 +88,52 @@ add_action('wp_footer', function () {
     if (!get_post_meta(get_queried_object_id(), 'fea_audio_url', true)) return;
     ?>
     <script>
-    document.querySelectorAll('audio[data-fea-audio-track]').forEach(function (audio) {
-        var fired = false;
-        audio.addEventListener('play', function () {
-            if (fired || typeof gtag !== 'function') return;
-            fired = true;
-            gtag('event', 'audio_play', {
-                post_id: audio.dataset.postId,
-                voice: audio.dataset.voice
+    (function () {
+        function hex(buffer) {
+            return Array.from(new Uint8Array(buffer)).map(function (n) {
+                return n.toString(16).padStart(2, '0');
+            }).join('');
+        }
+        document.querySelectorAll('[data-fea-audio-verified-play]').forEach(function (button) {
+            button.addEventListener('click', async function () {
+                var wrap = button.closest('.fea-audio');
+                var audio = wrap.querySelector('audio[data-fea-audio-track]');
+                var status = wrap.querySelector('.fea-audio-status');
+                button.disabled = true;
+                status.textContent = 'Verificando audio…';
+                try {
+                    // Se descarga el objeto entero una vez y se valida su hash. Sólo
+                    // entonces se crea un blob local: el <audio> no hará Range contra
+                    // CDN y jamás podrá mezclar fragmentos de otro MP3.
+                    var response = await fetch(button.dataset.src, {cache: 'no-store'});
+                    if (!response.ok) throw new Error('HTTP ' + response.status);
+                    var bytes = await response.arrayBuffer();
+                    var digest = hex(await crypto.subtle.digest('SHA-256', bytes));
+                    if (digest !== button.dataset.sha256) throw new Error('La copia recibida no coincide con el audio verificado');
+                    audio.src = URL.createObjectURL(new Blob([bytes], {type: 'audio/mpeg'}));
+                    audio.hidden = false;
+                    button.hidden = true;
+                    status.textContent = '';
+                    await audio.play();
+                } catch (error) {
+                    status.textContent = 'No se pudo verificar el audio. Inténtalo de nuevo.';
+                    button.disabled = false;
+                    console.error('Fe Adulta audio verification failed:', error);
+                }
             });
         });
-    });
+        document.querySelectorAll('audio[data-fea-audio-track]').forEach(function (audio) {
+            var fired = false;
+            audio.addEventListener('play', function () {
+                if (fired || typeof gtag !== 'function') return;
+                fired = true;
+                gtag('event', 'audio_play', {
+                    post_id: audio.dataset.postId,
+                    voice: audio.dataset.voice
+                });
+            });
+        });
+    }());
     </script>
     <?php
 });
diff --git a/scripts/sync_audio_to_prod.py b/scripts/sync_audio_to_prod.py
index fef4204..9a1ef30 100644
--- a/scripts/sync_audio_to_prod.py
+++ b/scripts/sync_audio_to_prod.py
@@ -19,6 +19,7 @@ Rollback (despublica en prod lo que este script publicó):
 from __future__ import annotations
 
 import argparse
+import hashlib
 import json
 import os
 import subprocess
@@ -144,16 +145,21 @@ def prod_helper(subcmd: str, *args: str) -> str:
     return _ssh_text(_remote_wrap(inner), timeout=60)
 
 
-def prod_upload_mp3(post_id: int) -> None:
+def prod_upload_mp3(post_id: int) -> str:
     src = LOCAL_TTS_DIR / f"{post_id}.mp3"
     data = src.read_bytes()
+    local_sha256 = hashlib.sha256(data).hexdigest()
     remote_path = f"{PROD_UPLOADS_TTS}/{post_id}.mp3"
     _ssh_upload_bytes(data, remote_path)
-    # Verificación de tamaño: no fiarse ciegamente del rc=0 de ssh. `wc -c` debe
-    # correr (y resolver la redirección) DENTRO del contenedor — ver _remote_wrap.
+    # Verificación de tamaño+contenido: un rc=0 de ssh no acredita que el asset
+    # sea el mismo. El hash se persiste como meta y permite playback verificado.
     remote_size = int(_ssh_text(_remote_wrap(f"wc -c < {remote_path}")).strip())
     if remote_size != len(data):
         raise RuntimeError(f"tamaño no coincide tras subir #{post_id}: local={len(data)} remoto={remote_size}")
+    remote_sha256 = _ssh_text(_remote_wrap(f"sha256sum {remote_path} | cut -d' ' -f1")).strip()
+    if remote_sha256 != local_sha256:
+        raise RuntimeError(f"SHA-256 no coincide tras subir #{post_id}: local={local_sha256} remoto={remote_sha256}")
+    return local_sha256
 
 
 def prod_remove_mp3(post_id: int) -> None:
@@ -185,8 +191,9 @@ def sync_one(post_id: int, state: dict, *, dry_run: bool) -> str:
         return "PLAN: subiría mp3 + setaudio"
 
     voice = local_meta(post_id, "fea_audio_voice") or "NicoFeadulta2026"
-    prod_upload_mp3(post_id)
+    sha256 = prod_upload_mp3(post_id)
     prod_helper("setaudio", str(post_id), f"/wp-content/uploads/tts/{post_id}.mp3", voice)
+    prod_helper("setflag", str(post_id), "fea_audio_sha256", sha256)
     if post_id not in state["synced"]:
         state["synced"].append(post_id)
         save_state(state)